With just a day to go before the United States midterm elections on November 3, the country's political temperature has risen sharply. The vote, the first nationwide test of President Donald Trump's second term, will decide the balance of power in both chambers of Congress, the leadership of dozens of states and the direction of federal legislation for the next two years.
National polls show Democrats ahead in the race for the House of Representatives, while seven Senate contests remain fiercely competitive and several governorships could change hands. Nearly 50 million Americans have already cast their ballots across the country.
The central question is whether Democrats can break the Republican hold on Congress, or whether Trump's party will retain its grip. Voters will elect all 435 members of the House, 35 senators, including 33 regular seats and two special elections, and governors in 36 states.
Republicans currently hold 53 seats in the 100-member Senate. Democrats hold 45, and the two independents, Bernie Sanders and Angus King, caucus with them, giving Democrats an effective 47.
To win the chamber, Democrats need a net gain of at least four seats. In the House, current membership stands at 218 Republicans, 214 Democrats, one independent aligned with Republicans and two vacancies.
A majority requires 218 seats, meaning even a small shift could change control. The generic congressional ballot, which measures which party voters prefer nationally, shows Democrats ahead.
RealClearPolling's average for October 9 to 30 puts Democrats at 51.8% and Republicans at 43.3%, a lead of 8.5 points. An NBC News poll conducted from October 28 to 30 showed Democrats leading 52 to 45.
Emerson College, polling from October 24 to 26, found a 52 to 42 lead, The Harvard-Harris survey showed a narrower margin of 52 to 48. Ballotpedia's polling index of October 30 also put the Democratic lead at about eight points.
But national numbers do not translate directly into seats. House members are elected in 435 separate districts, and a party can win the national popular vote while still losing individual contests.
In its October 30 ratings, the Cook Political Report classified 222 seats as leaning towards Democrats, 195 towards Republicans and 18 as toss-ups. These figures combine its "solid", "likely" and "lean" categories and are assessments of competitiveness, not projected results.
Cook shifted several districts towards Democrats in the final week of October, and media coverage of its update discussed scenarios in which Democrats could gain between 12 and 25 seats. Inside Elections and Sabato's Crystal Ball also moved several Republican-held seats into more competitive categories during October.